First declension rule for when an alpha stays throughout the singular
The ειρish like alphas

Interaction of a sigma with some letters
The sigma is a snake, swallowing ζany and νaughty dentists (dentals)

Letter following an ευ or αυ that changes the upsilon to be pronounced f rather than v in reconstructed Koine
αυ or ευ followed by a πoodle, a χrazy κat on a ξylophone, or a θinking τurtle is pronounced with an f